If this is true it's a welcome change.
It means that any existing PTSB customer whose mortgage balance is over €250k can re-fix at the above rates. (Those >€250k rates were previously only available to new customers.)
PTSB's webpage of rates
appears to confirm that, although it seems that there are typos in the "Existing Home Loan Customers – High Value Mortgages" table. (It says "New Business" instead of "Existing Business".)
No matter where you are on the property ladder we have a mortgage rate that will suit you. View our up to date mortgage interest rates.
www.permanenttsb.ie
This wording is misleading. As far as I can tell, it just means that if you are in the middle of a PTSB fixed rate, your interest rate won't change. (No surprises there.) It does
not mean that existing PTSB customers can re-fix at the old, lower rates.